In delivery
The Village Manly, Stage 3
Manly, Brisbane
Retirement apartments on the heritage Lota House site, built alongside an operating aged care community.
- Client
- The Village Retirement Group
- Builder
- FKG Group
Image: FKG Group
Home / Moisture testing and floor preparation
Moisture testing and floor preparation
Every floor we lay starts with the slab. We test moisture, check flatness and prepare the substrate before anything goes down, so the floor carries its warranty and stays down.
The slab decides how the floor performs.
Most flooring failures don’t start with the flooring. They start with the slab: moisture still coming out of the concrete, an uneven surface, or a weak, contaminated top layer. Adhesives lose their bond, vinyl lifts or bubbles, and timber cups or gaps. Fixing it after handover means pulling up a finished floor.
We treat floor preparation as part of the flooring package, not an extra. It’s tested, priced and agreed up front, so it doesn’t turn into a surprise variation halfway through the program.
Our testing follows AS 1884:2021, the Australian Standard for installing resilient floor coverings, together with each manufacturer’s own moisture and flatness limits. If a floor won’t meet the manufacturer’s requirements, we tell you before it goes down.
- Moisture testingCalibrated relative humidity (RH) testing of the slab to AS 1884:2021, with results recorded against the flooring manufacturer’s limits.
- Diamond grindingRemoving laitance, curing compounds, old adhesive and high spots, with dust controlled to the 2023 silica regulations (see BFTB-002).
- Levelling and smoothingArdex levelling and smoothing compounds to bring the floor within the manufacturer’s flatness tolerance.
- Moisture barriersArdex moisture barriers as standard, so the barrier, primer and levelling compound form one complete Ardex system with a single system warranty. Other systems are used only where the project specifies them.
- RepairsJoints, cracks and damaged areas repaired so they don’t show through the finished floor.
- ProtectionRhino board and Polyweave protection after installation, through to handover.
How we prepare a floor.
Moisture becomes a known quantity before the program is locked in, not a problem discovered on install day.
Test early
Slabs tested as soon as we have access, so results are in hand while there’s still time to act on them.
Report
Results recorded and shared with the builder, with any area outside tolerance flagged.
Agree the fix
Grinding, levelling or a moisture barrier priced and agreed before work starts.
Prepare
The substrate prepared area by area to the builder’s program.
Install and protect
Flooring installed to the manufacturer’s requirements, then protected through to handover.
Why slabs stay wet, and what we do about it.
New concrete holds far more water than it needs to cure, and it gives that water up slowly. As a guide, AS 1884:2021 recommends a minimum of 28 days per 25 mm of slab thickness in ideal drying conditions, and site conditions are rarely ideal. Slabs that are covered early, poured over membranes or podiums, rained on before the roof goes on, or closed up without airflow can stay wet for months.
Lay a resilient or timber floor over a slab that is still releasing moisture and the adhesive breaks down. Vinyl bubbles and lifts at the seams, timber cups and gaps, and the failure often shows up months after handover, when the only fix is pulling up a finished floor.
That is why the readings go to the builder in writing. Where a slab tests above the 80% RH limit, we notify the builder and ask for a written direction before we proceed: either an Ardex moisture barrier as a variation, or proceed without treatment with the builder accepting the substrate risk. Our own readings are an early warning, not an independent assessment. Where a formal report is needed, it should come from a third party with no interest in the result.
Download Technical Bulletin BFTB-001 (PDF) All technical bulletins
- The limit80% RH for most resilient floors under AS 1884:2021, or the manufacturer’s own limit where it is lower.
- Readings in writingResults recorded and sent to the builder, so the slab’s condition is on the record before anything goes down.
- Written directionAbove the limit, nothing is installed until the builder directs how to proceed.
- Planned at tenderMoisture risk is raised and priced at tender, not discovered mid-program.
Floor preparation on our projects.
From slab grinding in new apartment towers to moisture barriers in buildings next to operating communities.
In delivery
Completed
TAFE Queensland, Robina Campus
Robina, Gold Coast
A multi-level fitout of TAFE Queensland’s newest campus, recognised as Australia’s first sustainable vocational education and training campus. Commercial training kitchens, hair and beauty studios, lecture rooms, a gym, classrooms, and a conference and bar level for events.
- Client
- TAFE Queensland
- Builder
- Shape Australia
- Designer
- AEQ Architects
- Client project manager
- EY
Image: Shape Australia
Completed 2024
The Witton
Indooroopilly, Brisbane
Two boutique residential buildings with a rooftop pool and terrace overlooking the river and city.
- Builder
- Mosaic Construction
- Architect
- Rothelowman
Photo: Mosaic Property Group
Common questions.
How long does a new concrete slab take to dry before flooring?
It depends on the slab’s thickness and mix, how it was cured, and site conditions such as airflow and air-conditioning. Rules of thumb are only a rough guide, so the reliable answer is a moisture test. We test early so the program can be planned around the result.
What standard covers moisture testing for floor coverings in Australia?
AS 1884:2021 sets out installation practices for resilient floor coverings such as vinyl and linoleum, including how the substrate is tested for moisture. Flooring manufacturers also set their own moisture and flatness limits, and meeting them is what keeps the floor under warranty.
What happens if the slab is too wet?
If the program allows, the slab is given more time to dry and re-tested. If it doesn’t, we apply an Ardex moisture barrier under the levelling compound, so the whole substrate is one Ardex system with a single system warranty. It’s priced for approval before any work goes ahead.
Does timber and hybrid flooring need moisture testing too?
Yes. Engineered timber, hybrid and laminate manufacturers all set moisture limits for the subfloor, and direct-stick timber is especially sensitive to moisture in the slab. We test before every timber, hybrid and resilient floor we install, not just vinyl.